my second loss

[danny zubot]

You could stand to add a bit of two part buffer. Washing soda and baking soda combined. This will raise your Carbonates while maintaining the same PH, provided you know what your PH is at. Washing soda is just baking soda that has been baked at 250 to 300 degrees for a couple of hours. This burns off a carbon atom resulting in an adverse effect on PH than that of baking soda. It raises PH, only it is 6 times stronger so a ratio of 6 baking to 1 part washing soda is required to maintian neutral ph.

I'd stick with water changes for now because so many other levels are off.